2010-02-23 20:59:33

by Scott Ellis

Subject: [PATCH] omap2_mcspi.c: NULL pointer dereference

Check spi->controller_state before dereferencing.

Shows up NULL here when using spi_alloc_device()/spi_add_device()
and spi_add_device() fails before spi_setup(). Calling spi_dev_put()
on the leftover spi_device results in the error.

Signed-off-by: Scott Ellis <[email protected]>

drivers/spi/omap2_mcspi.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index ba1a872..b1f82c1 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -751,11 +751,13 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];

- /* Unlink controller state from context save list */
- cs = spi->controller_state;
- list_del(&cs->node);
+ if (spi->controller_state) {
+ /* Unlink controller state from context save list */
+ cs = spi->controller_state;
+ list_del(&cs->node);

- kfree(spi->controller_state);
+ kfree(spi->controller_state);
+ }

if (mcspi_dma->dma_rx_channel != -1) {
omap_free_dma(mcspi_dma->dma_rx_channel);

2010-02-25 11:14:30

by Felipe Contreras

Subject: Re: [PATCH] omap2_mcspi.c: NULL pointer dereference

On Tue, Feb 23, 2010 at 9:36 PM, Scott Ellis <[email protected]> wrote:
> Check spi->controller_state before dereferencing.
>
> Shows up NULL here when using spi_alloc_device()/spi_add_device()
> and spi_add_device() fails before spi_setup(). Calling spi_dev_put()
> on the leftover spi_device results in the error.

This should go to the linux-omap mailing list.

--
Felipe Contreras